1998 to 2005
Since the transition of the program in fiscal year 1998 (FY98), the U.S. Army Corps of Engineers (USACE) has made significant progress at the Latty Site. The primary goal for Latty is to restrict the release of contaminated materials and minimize their potential impact on human health, wildlife and the environment.
In 1999, USACE completed construction of the HISS/Latty Avenue rail spur, which is capable of holding 11 rail cars, or 770 cubic yards of material. USACE also completed negotiations with an 8(a) woman-owned small business for a firm fixed-price contract to remove the two Eastern Piles. Also in 1999, USACE also renegotiated the St. Louis Utility Response Plan for all underground utilities affected by contamination from the MED/AEC. USACE trained and supported all affected utility companies. To protect human health and the environment, USACE supports utility companies and other property improvements on properties potentially impacted by MED/AEC contamination.
In March 1998, USACE prepared an Engineer Evaluation/Cost Analysis (EE/CA) proposing to remove the HISS piles and impacted soil from three adjacent Latty Avenue properties until a comprehensive cleanup could be achieved. The proposal received public approval, and plans were developed to allow work to proceed. USACE chose to expedite the removal of the HISS piles to protect human health and the environment.
USACE started removal of the HISS piles in spring 2000. Removal started with East Piles 1 and 2 located at VP-2L, adjacent to HISS. Work continued on the removal of the piles located on the HISS property. Contaminated materials from Spoil Piles A and B, Supplemental Pile and then the Main Pile were removed. Removal of the HISS piles was completed in fall 2001. Over 52,000 cubic yards of contaminated material was removed and transported by covered gondola cars for disposal at an out-of-state licensed or properly permitted facility.
The Record of Decision (ROD) presented the Final Remedy for the site (as opposed to the EE/CA, which presented an interim action.) The ROD – which addressed not only the St. Louis Airport Site, but the Latty Avenue Site and the SLAPS Vicinity Properties Site as well – was the result of USACE investigations and CERCLA planning activities that had been occurring concurrent with the EE/CA removal action at SLAPS. USACE developed cleanup alternatives and presented them to the public for review in the Feasibility Study (FS) and Proposed Plan (PP) in May 2003. Comments on the documents were accepted through July 14, 2003. The public’s input was considered, and a final ROD (Record of Decision for the North St. Louis County Sites, dated Sept. 2, 2005) was issued in September 2005. The final remedy consisted of excavation to achieve remediation goals:
- top 6-inch layer averaged over any 100 square-meter area: 5 picocuries per gram (pCi/g) Ra-226/14 pCi/g Th-230/50 pCi/g U-238 above background;
- subsurface soil (below the top 6 inches) averaged over any 100 square-meter area and averaged over a 6-inch thick layer of soil: 15 pCi/g Ra-226/15 pCi/g Th-230/50 pCi/g U-238 above background;
- Sediment below the mean water gradient will be removed if radionuclide concentrations averaged over any 100 square-meter area:: 15 pCi/g Ra-226/43 pCi/g Th-230/150 pCi/g of U-238 above background.
- All accessible contaminated soils/material will be disposed of off-site at a properly permitted facility.
2005 to present
Before any actions are performed on a FUSRAP property, a Pre-Design Investigation (PDI) is performed. The PDI summarizes the existing/historical data, defines additional analytical data needs and determines if residual radiological contamination above the ROD remediation goals (RGs) are present on the property. Once the property has been sampled and completely characterized, a Pre-Design Investigation Report (PDIR) is prepared that documents the results of the PDI activities that were performed at the property.
If the data presented in the PDIR meets ROD RGs, a Final Status Survey Evaluation (FSSE) is then performed.
A Final Status Survey Evaluation (FSSE) provides detailed information regarding:
(1) the survey process for soil and structures (including the design, methodology and approach for area-weighted averaging);
(2) the assessment of survey results for soil and structures (including statistical tests and data quality);
(3) an assessment of residual risk and dose; and
An FSSE is conducted (at the St. Louis FUSRAP Sites) to ensure that any residual radioactivity complies with the criteria specified in the ROD (USACE 2005) for protecting human health and the environment.
If a property meets the ROD RGs during the PDIR/FSSE process, the property can be released. USACE then prepares a PDIR/FSSE for that property.
If the data in a PDIR demonstrates that the property doesn't meet ROD RGs. the property must be remediated. A Remedial Design/Remedial Action Work Plan (RD/RAWP) is prepared to remediate the property. The remediation is completed when the property meets the FSSE.
A Post-Remedial Action Report (PRAR) document is prepared when remedial activities are completed on a property. The PRAR documents the history, the site conditions and the response actions that occurred on a property. The collection of individual PRARs for each portion of the site will be used as the supporting documentation for development of the Final Close-Out Report.
After remedial activities are completed and the property meets the ROD RGs, properties are released under a PRAR/FSSE.
In 2010, USACE released the PRAR/FSSE for the following properties:
· Parcel 10K530087 (9205 Latty Ave., Hazelwood, MO)
· VP 1L (9151 Latty Ave., Berkeley, MO) (Excluding building interior. Interior remedial activities completed in 2013).
In 2012, USACE released the PRAR/FSSE for the following properties:
· VP-2L (9150 Latty Ave., Berkeley, MO)
· VP 3L (9060 Latty Ave., Berkeley, MO)
· VP 4L (8966 Latty Ave., Berkeley, MO)
· VP 5L (8942 Latty Ave., Berkeley, MO)
· VP 6L (8999 Seeger Industrial Drive, Berkeley, MO).
In 2013, USACE completed remedial activities in the interior of the main building:
· VP 1L (9151 Latty Ave., Berkeley, MO).